The present technology relates to a signal processing unit and a signal processing method, and particularly relates to a signal processing unit and a signal processing method that allow calculation of a pixel value for image output of a phase difference pixel, the pixel value causing image quality to be less degraded.
Recently, there has been proposed a solid-state image pickup unit having a pixel region in which a plurality of pixels are arranged in a matrix, the pixels including a phase difference pixel for detection of a focal point in addition to normal pixels for image output.
In such a solid-state image pickup unit, a pixel value for image output of the phase difference pixel is necessary to be correctively obtained. A correction method of the pixel value includes a method of obtaining such a corrected pixel value through gain multiples of the pixel value of the phase difference pixel, and a method of obtaining such a corrected pixel value based on pixel values of peripheral pixels in the periphery of the phase difference pixel.
Japanese Unexamined Patent Application Publication No. 2012-4729 (JP-A-2012-4729) discloses a method of obtaining a pixel value for image output of a phase difference pixel by switching between an interpolated value through gain multiples of the phase difference pixel and an interpolated value based on pixel values of peripheral pixels depending on total luminance and edge quantity of the pixel values of the peripheral pixels.
For example, Japanese Unexamined Patent Application Publication No. 2010-62640 (JP-A-2010-62640) proposes a method of determining a synthesized value in a predetermined synthetic ratio of an interpolated value through gain multiples of a phase difference pixel to an interpolated value based on pixel values of peripheral pixels as a pixel value for image output of the phase difference pixel. In the method disclosed in JP-A-2010-62640, the synthetic ratio is determined based on a ratio σ/a of a standard deviation value σ to an average a of peripheral same-color pixels of the phase difference pixel.